151 results about "Double-layer capacitance" patented technology

Partial fill of an electrochemical test strip is determined by making a DC determination of double layer capacitance from charging or discharging charge on a test strip containing sample, for example a blood sample to be tested for glucose. The measured double layer capacitance is compared to a reference value. The double layer capacitance may be determined as an integral or differential capacitance. Double layer capacitance may also be used for quality control to monitor the quality of electrode formation, particularly in strips using screen printed electrodes.

The present application is generally directed to ultrapure synthetic carbon materials having both high surface area and high porosity, ultrapure polymer gels and devices containing the same. The disclosed ultrapure synthetic carbon materials find utility in any number of devices, for example, in electric double layer capacitance devices and batteries. Methods for making ultrapure synthetic carbon materials and ultrapure polymer gels are also disclosed.

A system and method for estimating internal parameters of a lithium-ion battery to provide a reliable battery state-of-charge estimate. The method uses a two RC-pair equivalent battery circuit model to estimate the battery parameters, including a battery open circuit voltage, an ohmic resistance, a double layer capacitance, a charge transfer resistance, a diffusion resistance and a diffusion capacitance. The method further uses the equivalent circuit model to provide a difference equation from which the battery parameters are adapted, and calculates the battery parameters from the difference equation.

The present application is generally directed to energy storage materials such as activated carbon comprising enhanced particle packing properties and devices containing the same. The energy storage materials find utility in any number of devices, for example, in electric double layer capacitance devices and batteries. Methods for making the energy storage materials are also disclosed.

A method of pumping fluid including the steps of providing an electrokinetic pump comprising a pair of double-layer capacitive electrodes having a capacitance of at least 10−2 Farads / cm2 and being connectable to a power source, a porous dielectric material disposed between the electrodes and a reservoir containing pump fluid; connecting the electrodes to a power source; and moving pump fluid out of the reservoir substantially without the occurrence of Faradaic processes in the pump. The invention also includes an electrokinetic pump system having a pair of double-layer capacitive electrodes having a capacitance of at least 10−2 Farads / cm2; a porous dielectric material disposed between the electrodes; a reservoir containing pump fluid; and a power source connected to the electrodes; the electrodes, dielectric material and power source being adapted to move the pump fluid out of the reservoir substantially without the occurrence of Faradaic processes in the pump.

The present application is generally directed to energy storage materials such as activated carbon comprising enhanced particle packing properties and devices containing the same. The energy storage materials find utility in any number of devices, for example, in electric double layer capacitance devices and batteries. Methods for making the energy storage materials are also disclosed.

Partial fill of an electrochemical test strip is determined by making a DC determination of double layer capacitance from charging or discharging charge on a test strip containing sample, for example a blood sample to be tested for glucose. The measured double layer capacitance is compared to a reference value. The double layer capacitance may be determined as an integral or differential capacitance. Double layer capacitance may also be used for quality control to monitor the quality of electrode formation, particularly in strips using screen printed electrodes.

A method of fabricating a two-layer capacitive touch sensor panel comprising the following steps: a) depositing a first transparent electrically conductive layer on a transparent cover sheet; b) forming a pattern in the transparent electrically conductive layer to create a first set of discrete electrode structures; c) depositing a transparent dielectric layer over the discrete electrode structures; d) depositing a second transparent electrically conductive layer onto the transparent dielectric layer; e) forming a pattern in the transparent electrically conductive layer to create further discrete electrode structures by laser ablation, this pattern either not penetrating or penetrating only part way through the dielectric layer so as to avoid damaging the first set of discrete electrode structures; f) forming electrical connections or vias between the two transparent electrically conductive layers through the dielectric layer; and g) forming electrical connections between the transparent electrically conductive layer(s) and an electrical track or busbar formed at the periphery of the panel.) The method provides a maskless, chemical free way to fabricate a two-layer “cover integrated” sensor. A two-layer capacitive touch sensor panel fabricated by this method is also described

Methods and apparatuses for determining surface wetting of a rock material with changing well fluids. In general, the methods according to the invention include measuring electrical impedance spectroscopy (“EIS”) for a system simulating downhole conditions for the wetting of a surface. Methods and apparatuses for making EIS measurements model double-layer capacitance at a downhole surface in a well, from which the nature and quantification of the wetting of the surface can be inferred.

A method for electrochemical impedance spectroscopy uses interdigitated electrodes functionalized with a first species and nanoparticles functionalized with a second species that preferentially attaches to the first species. The nanoparticles are composed of a material with a dielectric constant (k value) greater than 2. The chemically functionalized electrodes are then exposed to a solution containing the chemically functionalized nanoparticles which then become immobilized on the electrodes through the attachment of the first species to the second species. The impedance spectrum is measured and an amount of the first species is then determined from the measured spectrum. Because the high-k dielectric nanoparticles increase the double-layer capacitive impedance, the sensitivity of determining the amount of the first species attached to the second species is enhanced.

The invention discloses an eddy flow concentration sparse gas-solid two-phase flow capacitance chromatography imaging measurement method and device which belong to gas-solid two-phase flow measurement technology. The device includes an eddy flow concentration apparatus connected with a sparse gas-solid two-phase flow channel, the eddy flow concentration apparatus is connected with a control valve and an air pump, an outlet of the air pump is connected to the sparse gas-solid two-phase flow channel. The method includes that after eddy flow concentration of the sparse gas-solid two-phase flow, solid particle is concentrated at wall surface, solid particle concentration is measured by single-layer capacitance sensor, speed is measured by double-layer capacitance sensor, and mass flow of the solid particle can be calculated by combining the solid particle concentration and the speed. Capacitance chromatography imaging technology is used to measure improved measurement precision. The measurement method and sensor provided by the present invention integrate concentration, speed and mass flow measurement, have advantages of simple structure and convenient calibration, solve problem of measuring the sparse gas-solid two-phase flow in large-diameter pipeline by using the capacitance chromatography imaging technology, and have wide application field.

The invention discloses a zinc oxide (ZnO) / reduced graphene oxide / polypyrrole (ZnO / RGO / PPy) ternary composite material, which belongs to the technical field of composite material. The ZnO / RGO / PPy ternary composite material is prepared by a two-step method, including preparing a uniformly-dispersed binary composite material ZnO / reduced graphene oxide (ZnO / RGO), and polymerizing pyrrole (Py) monomer by chemical oxidation method by using the binary composite material as a template to obtain the ZnO / RGO / PPy ternary composite material. The ZnO / RGO / PPy ternary composite material prepared by the invention has both the electric double layer capacitance characteristics of RGO and pseudocapacitor energy storage characteristics of ZnO and Ppy, so that the composite material can show high electrochemical capacitance behavior, excellent rate capability, good circulation stability, and has high energy densigh and power density, , and can be used as the electrode material of a super capacitor.

A dry titanium nitride (TiN) powder abrasion method roughens the surface of a valve metal foil for use as a cathode in an electrolytic capacitor. This increases the surface area of the foil, thereby increasing the double-layer capacitance of the cathode, and also mechanically alloys TiN powder to the surface of the foil, thereby increasing the pseudo-capacitance of the cathode. In one embodiment, a piece of thin titanium foil is mounted on a hard metal backing and at least one surface of the foil is abraded with fine titanium nitride powder. In another embodiment, a continuous metal foil tape is fed into a bead blasting box and at least one surface of the metal foil tape is abraded with TiN powder delivered by a bead blasting nozzle located within the bead blasting box. Accordingly, a cathode having increased capacitance capability is provided to more closely match the capacitance of a poly-anode stack.

The invention discloses a carbon-based ternary composite electrode material for a super capacitor and a preparation method for the carbon-based ternary composite electrode material. The preparation method for the carbon-based ternary composite electrode material comprises the following steps of: firstly, performing ultrasonic dispersion on reactivated active carbon and a nanometer metallic oxide to prepare an active carbon / nanometer metallic oxide composite material; controlling the molar ratio of the active carbon / nanometer metallic oxide composite material to aniline monomer to be (3:1)-(10:1) through an in-situ polymerization method, and performing stirring reaction for 5-25h to obtain the carbon-based ternary composite electrode material for the super capacitor. According to the material, electric double-layer capacitance is provided for the super capacitor by effectively utilizing high-specific surface area active carbon. By combining with Faraday pseudocapacitance provided by conductive polyaniline, and meanwhile, by utilizing the high mechanical strength and a nanometer synergistic effect of the nanometer metallic oxide, the initial specific capacitance of the material in an organic electrolyte can reach 178F / g, and if the material is circulated for 2000 times, the specific capacitance can still be kept to be 148F / g.

An active material of the present invention has fine pores formed in the interlayer of a carbon material capable of exhibiting electrochemical double layer capacitance. The fine pores are formed by forming an oxidized graphite structure combined with oxygen in the interlayer of a part or whole of the carbon material containing soft carbon and then removing a part or whole of oxygen in the interlayer. A method for producing an energy storage active material for use in an electrochemical double layer capacitor comprises pre-treating a carbon material through heat treatment and oxidizing the pre-treated carbon material using an oxidant. The method further comprises reducing the oxidized carbon material through heat treatment. The interlayer distances of an active material for respective steps, measured by a powder X-ray diffraction method, are 0.33˜0.36 nm in the pre-treatment step, 0.5˜2.1 nm in the oxidation step, and 0.34˜0.5 nm in the reduction step.

An anode and cathode for an electrolytic cell are configured as a low inductance transmission line to enable control of an interphase at an electrode surface. The anode and cathode are coupled to a switched current source by a low inductance path that include a parallel plate transmission line, a coaxial transmission line, or both. The switched current source provides switching between current sources at three or more voltages to provide fast charging and discharging of the double-layer capacitance associated with the electrode surface.

The invention relates to a preparation method for conductive polymer modification activated carbon electrode materials in a super capacitor, which comprises the following steps: conductive polymer monomers are added into ionic liquid to obtain A solution with the monomer concentration of 0.01-0.5mol / L; the A solution is added into an electrolytic cell deployed with three electrodes; ampere density of 1-10 mA / cm2 is applied to an activated carbon electrode; the electrochemical polymerization is carried out under the protection of nitrogen; after the polymerization is finished, a layer of even conduction polymer film can be obtained on an activated carbon working electrode. The preparation method has the beneficial effects that by using conductive polymer modification activated carbon electrodes, the double layer capacitance of the activated carbon not only can be used, but also the pseudo-capacitance of the conductive polymers can be used for increasing the specific capacitance of the capacitor; compared with a pure activated carbon electrode, the specific capacitance is increased by 2-3 times; and the electrode has high conductivity, fast charge and discharge capability and better circulation stability.

The invention provides a preparation method for metal active carbon used in electrodes, which is characterized in that coal is used as raw material, metal compounds, binder and surfactant are added, uniformly mixed, layered and molded to get strip. After being dried, the strip is carbonized under certain temperature and activated with steam, carbon dioxide or the mixtures as activator under a certain temperature to get metal active carbon at last. The preparation method for electrode metal active carbon has the advantages of rich material resources and low price, and thus can be used to prepare metal active carbon with abundant pores, controllable pore structure, large quantity of mesopores, and double effects of double-layer capacitance and quasi-capacitance.

The present invention relates to a flexible supercapacitor with with NiS-MoS2 heterogeneous nano-sheet array structure based on carbon cloth loading and a preparation method thereof, belonging to thetechnical field of new energy material and device preparation. The flexible supercapacitor grows high-purity, high-density and high-orientation carbon cloth-loaded NiS-MoS2 heterogeneous nanosheet array by using anode material, carbon cloth coated with activated carbon as cathode material, PVA / KOH gel as diaphragm and electrolyte respectively. The anode has the advantages of high purity, high density, tidy appearance, strict controllable growth condition, simple equipment and process, low cost, high capacitance and good charge-discharge stability. The cathode material has excellent conductivity and large double-layer capacitance. The preparation process of the capacitor is simple, economical and environmentally friendly, and no post-treatment is needed. The supercapacitor provided by the invention has the advantages of light weight, large capacity, good cycle charging and discharging stability, and good flexibility, and can be used for power supply equipment of wearable electronic devices.

The present application is generally directed to hydrated carbon material powder comprising carbon material and water and devices containing the same. The hydrated carbon material powder finds utility in any number of devices, for example, in electric double layer capacitance devices and batteries. Methods for making and use of the hydrated carbon material powder are also disclosed.

The invention relates to an asymmetric supercapacitor adding potassium ferricyanide and p-phenylenediamine to dipolar electrolyte and a preparation method. An anode is made of carbon material / cobalt hydroxide electrode, and a cathode is made of nickel foam or carbon material / activated carbon electrode. The electrolyte is aqueous alkaline solution and separates the positive pole chamber and the negative pole chamber by using the ion exchange membrane, and the positive electrolyte and the negative electrolyte are respectively added the potassium ferricyanide and the p-phenylenediamine. The energy storage device can realize the organic combination of supercapacitor and flow batteries, and the electrodes in the same supercapacitor can not only be used as a conductor of electronic transmission, but also contribute to a double-layer capacitance or pseudo capacitance. The electrolyte can transmit ions, and can store and release changes, so that the specific capacitance and the energy density are significantly improved. The capacitor can be assembled in the form of superposition, that is, a plurality of supercapacitors are connected in series and / or in parallel to form supercapacitor groups, or multiple groups of supercapacitor in series and parallel, thereby achieving the required voltage and current.

A method for obtaining information encoded on an electrochemical test strip is provided. The test strip has two electrodes disposed within a sample space and the information is encoded on the test strip prior to introduction of liquid sample. The method includes the step of introducing sample to the sample space so that the sample is in contact with the two electrodes within the sample space. In another step a value is determined that is representative of the double layer capacitance of the test strip and / or the equivalent capacitance of the test strip. The determined value is then translated into information reflecting a characteristic of the test strip prior to introduction of sample.

The invention discloses a bismuth / carbon supercapacitor battery and a preparation method thereof. The bismuth / carbon supercapacitor battery uses a bismuth electrode for providing Faraday capacitance, uses a carbon electrode for providing electric double-layer capacitance, and uses an alkaline solution as an electrolyte; the bismuth is metal bismuth powder with the particle size of 0.005-5 microns and has the specific surface area of 5-500m<2> / g; a preparation method of the metal bismuth powder comprises the following steps: mixing an auxiliary agent and bismuth ions with a certain concentration in a proper molar ratio to obtain a mixed solution, then dropwise adding a reducing agent into the mixed solution, and reacting to prepare metal bismuth powder material. When the bismuth / carbon supercapacitor battery is prepared, the bismuth electrode is used as a capacitance limiting electrode, and the capacitance of the carbon electrode is 0-30% higher than that of the bismuth electrode. The bismuth / carbon supercapacitor battery has the working voltage of 0-1V, and has the specific capacitance of 258mAh / g when the current density is 0.5A / g. The bismuth / carbon supercapacitor battery has good electrochemical performance, is environment-friendly, and is a novel chemical power supply with a wide application prospect.

The present invention provides there is provided an electrochemical biosensor electrode structure that includes: a working electrode and a reference electrode used as electrodes for sample measurement being arranged separately from each other in lengthwise direction of a sample insertion path, the working electrode and the reference electrode each having at least one projection and at least one recess alternately arranged on a portion thereof corresponding to the sample insertion path, the projection of the working electrode being correspondingly adjacent to the recess of the reference electrode, the recess of the working electrode being correspondingly adjacent to the projection of the reference electrode; and at least two sample recognition electrodes used as electrodes for sample recognition being separated from each other and arranged adjacent and parallel to the working electrode and the reference electrode. The present invention minimizes the effect of the double layer capacitance and independently applies the sample recognition signal to accurately detect the sample insert time and velocity.

The invention pertains to the field of electrochemistry materials, and discloses a grapheme electrode plate and a preparation method thereof. The grapheme electrode plate comprises a current collector and an electrode active material coating the surface of the current collector. The electrode active material comprises, by mass, 90-96% of graphene, 2-5% of conductive agent, and 2-5% of binder. According to the graphene electrode plate provided in the invention, a oxygen-containing functional group is formed on the surface of the grapheme, so when the grapheme electrode plate is used in a supercapacitor electrode, the oxygen-containing functional group and ions in an electrolyte can be subjected to Faraday redox reaction to increase the pseudocapacitance, so the graphene electrode plate has both of the electrical double-layer capacitance and the pseudocapacitance, so that the supercapacitor capacity can be improved.

Methods and apparatuses for determining surface wetting of a metallic material with changing well fluids. In general, the methods according to the invention include measuring electrical impedance spectroscopy (“EIS”) for a system simulating downhole conditions for the wetting of a surface. Methods and apparatuses for making EIS measurements model double-layer capacitance at a downhole surface in a well, from which the nature and quantification of the wetting of the surface can be inferred.